The present invention relates to a method of using an aqueous composition or dispersion containing a water-soluble or water-dispersible synthetic polymer, and metal working fluid composition formed thereof.
The present invention relates to a method of using an aqueous composition or dispersion containing a water-soluble or water-dispersible synthetic polymer, and to the resultant metal working fluid composition formed thereof. When added to a metal working fluid composition, the aqueous composition or dispersion imparts desirable properties to the resultant metal working fluid composition.
A variety of compositions or materials are needful of certain properties to obtain a desirable end product.
Shear stability of the composition is needed under spraying conditions due to the shear stress the composition undergoes under spraying conditions at the discharge point at the nozzle and also the shear input experienced at the pump.
The shear rate that a composition is typically subjected to at the discharge point of the nozzle or at the pump can be as low as zero to as high as 106 reciprocal seconds, i.e., from 0 to 106 sxe2x88x921. Low shear is from 1,000 to 99,000 sxe2x88x921. High shear is greater than 99,000 sxe2x88x921. In terms of shear stress, the shear stress that a composition is typically subject to at the nozzle or at the pump can be from 1 pascal to 30,000 pascals.
That is, a composition sprayed from a sprayer undergoes shear stress. Under these conditions, the composition is released in the form of droplets. Often the droplets are small enough to be classified as a mist or an aerosol. Misting, or the formation of a mist, is considered undesirable, because it represents a loss of fluid. Also, the mist or aerosol created is considered a contaminant in the surrounding air. For example, an aerosol, upon discharge from a sprayer, can disperse beyond a selected target area, and can therefore contaminate crops or harm persons in a vicinity located beyond the selected target area. Therefore, it is very beneficial to impart aerosol control or mist control properties, referred to as an effective amount of antimist performance, to such compositions to prevent these undesirable effects created by misting.
Metal cutting operations often involve a work piece which rotates at relatively high speed, and a cutting tool both of which are lubricated by a metal working fluid. Under these conditions, the metal working fluid is frequently thrown from the surface of the metal in the form of droplets. Often the droplets are small enough to be classified as a mist. Misting, or the formation of a mist is considered undesirable, because it represents a loss of the cutting fluid, and the cutting fluid mist is considered a contaminant in the air around the cutting machine. Therefore, mist control during metal working operations is desirable.
The present invention provides a method of using an aqueous composition or dispersion containing a water-soluble or water-dispersible synthetic polymer, wherein said aqueous composition or dispersion imparts aerosol control in combination with shear stability to a metal working fluid composition, whereby the resultant metal working fluid composition sustains a shear rate range of from about 1 to about 1,000,000 sxe2x88x921, and sustains a shear stress range of from about 1 pascal to about 500,000 pascals.
When shear stability is a property to be imparted according to the present invention, shear rate and shear stress under metal working conditions are factors in determining performance of a composition regarding shear stability.
When the aqueous composition or dispersion containing the polymer according to the present invention is added to a metal working fluid composition, the resultant composition has a shear stability such that it can sustain a shear rate range of from about 1 to about 1,000,000 sxe2x88x921, and can sustain a shear stress range of from about 1 pascal to about 500,000 pascals.
The present invention therefore provides for the ability to impart properties including aerosol control in combination with shear stability to a metal working fluid composition.
In a preferred embodiment, the aqueous composition or dispersion according to the present invention and as utilized in the resultant metal working fluid composition according to the present invention, comprises a polymer that is a copolymer formed by copolymerizing (A) a hydrophobic monomer selected from the group consisting of A(I) an alkyl substituted acrylamide compound having the formula: 
wherein R1 is a hydrogen or a methyl group and R2 and R3 are independently hydrogen or hydrocarbyl groups, provided that the total number of carbon atoms in R2 and R3 combined is between 2 and 36, and A(II) an acrylate ester of the following formula: 
where R1 is a hydrogen or a methyl group and R9 is a hydrocarbyl group containing between 1 and 20 carbon atoms; and (B) a hydrophilic monomer selected from the group consisting of:
B(I) acrylamido sulfonic acids having the formula: 
xe2x80x83wherein R4 is a hydrogen or a methyl group and R is an aliphatic or aromatic hydrocarbon group containing from 2 to 12 carbon atoms, preferably from 2 to 8 carbon atoms;
B(II) acrylamido disulfonic acids having the formula: 
xe2x80x83wherein R4 is a hydrogen or a methyl group and R is an aliphatic or aromatic hydrocarbon group containing from 2 to 12 carbon atoms, preferably from 2 to 8 carbon atoms, and
B(III) a styrene sulfonic acid having the formula: 
xe2x80x83wherein R4 is a H or a methyl group, and X+ is H or a cation selected from the group consisting of alkali metal cations, alkaline earth cations, cations of the transition metals: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and ammonium cations of the following formula:
R5R6R7R8N+
xe2x80x83wherein R5, R6, R7 , and R8 are independently hydrogen or hydrocarbyl groups, provided that the total number of carbon atoms in an ammonium cation does not exceed 21 carbon atoms, and further provided that if A is A(I), then the ratio of moles of A to B is from about 95:5 to about 1:99, and if A is A(II), then the ratio of moles of A to B is from about 75:25 to about 1:99. The ratio of moles of A to B for A(I) or for A(II) will vary within these ranges according to the particular method of use and resultant composition selected.
The polymer in the aqueous composition or dispersion according to the present invention and as utilized in the resultant metal working fluid composition of the present invention, also comprises a third monomer unit, (C).
The polymer is prepared by polymerization of the combination of (A), (B), and (C) monomer units. Unit (C) must be polymerizable with units (A) and (B).